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/* Copyright 2007-2010 Jozsef Kadlecsik (kadlec@blackhole.kfki.hu)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <assert.h> /* assert */
#include <errno.h> /* errno */
#include <stdlib.h> /* calloc, free */
#include <time.h> /* time */
#include <arpa/inet.h> /* hto* */
#include <libipset/linux_ip_set.h> /* enum ipset_cmd */
#include <libipset/debug.h> /* D() */
#include <libipset/session.h> /* ipset_session_handle */
#include <libipset/ui.h> /* IPSET_ENV_EXIST */
#include <libipset/utils.h> /* UNUSED */
#include <libipset/mnl.h> /* prototypes */
#ifndef NFNL_SUBSYS_IPSET
#define NFNL_SUBSYS_IPSET 6
#endif
/* Internal data structure for the kernel-userspace communication parameters */
struct ipset_handle {
struct mnl_socket *h; /* the mnl socket */
unsigned int seq; /* netlink message sequence number */
unsigned int portid; /* the socket port identifier */
mnl_cb_t *cb_ctl; /* control block callbacks */
void *data; /* data pointer */
};
/* Netlink flags of the commands */
static const uint16_t cmdflags[] = {
[IPSET_CMD_CREATE-1] = NLM_F_REQUEST|NLM_F_ACK|NLM_F_CREATE|NLM_F_EXCL,
[IPSET_CMD_DESTROY-1] = NLM_F_REQUEST|NLM_F_ACK,
[IPSET_CMD_FLUSH-1] = NLM_F_REQUEST|NLM_F_ACK,
[IPSET_CMD_RENAME-1] = NLM_F_REQUEST|NLM_F_ACK,
[IPSET_CMD_SWAP-1] = NLM_F_REQUEST|NLM_F_ACK,
[IPSET_CMD_LIST-1] = NLM_F_REQUEST|NLM_F_ACK|NLM_F_ROOT|NLM_F_MATCH|NLM_F_DUMP,
[IPSET_CMD_SAVE-1] = NLM_F_REQUEST|NLM_F_ACK|NLM_F_ROOT|NLM_F_MATCH|NLM_F_DUMP,
[IPSET_CMD_ADD-1] = NLM_F_REQUEST|NLM_F_ACK|NLM_F_EXCL,
[IPSET_CMD_DEL-1] = NLM_F_REQUEST|NLM_F_ACK|NLM_F_EXCL,
[IPSET_CMD_TEST-1] = NLM_F_REQUEST|NLM_F_ACK,
[IPSET_CMD_HEADER-1] = NLM_F_REQUEST,
[IPSET_CMD_TYPE-1] = NLM_F_REQUEST,
[IPSET_CMD_PROTOCOL-1] = NLM_F_REQUEST,
};
/**
* ipset_get_nlmsg_type - get ipset netlink message type
* @nlh: pointer to the netlink message header
*
* Returns the ipset netlink message type, i.e. the ipset command.
*/
int
ipset_get_nlmsg_type(const struct nlmsghdr *nlh)
{
return nlh->nlmsg_type & ~(NFNL_SUBSYS_IPSET << 8);
}
static void
ipset_mnl_fill_hdr(struct ipset_handle *handle, enum ipset_cmd cmd,
void *buffer, size_t len UNUSED, uint8_t envflags)
{
struct nlmsghdr *nlh;
struct nfgenmsg *nfg;
assert(handle);
assert(buffer);
assert(cmd > IPSET_CMD_NONE && cmd < IPSET_MSG_MAX);
nlh = mnl_nlmsg_put_header(buffer);
nlh->nlmsg_type = cmd | (NFNL_SUBSYS_IPSET << 8);
nlh->nlmsg_flags = cmdflags[cmd - 1];
if (envflags & IPSET_ENV_EXIST)
nlh->nlmsg_flags &= ~NLM_F_EXCL;
nlh->nlmsg_seq = ++handle->seq;
nfg = mnl_nlmsg_put_extra_header(nlh, sizeof(struct nfgenmsg));
nfg->nfgen_family = AF_INET;
nfg->version = NFNETLINK_V0;
nfg->res_id = htons(0);
}
static int
ipset_mnl_query(struct ipset_handle *handle, void *buffer, size_t len)
{
struct nlmsghdr *nlh = buffer;
int ret;
assert(handle);
assert(buffer);
if (mnl_socket_sendto(handle->h, nlh, nlh->nlmsg_len) < 0)
return -ECOMM;
D("message sent");
ret = mnl_socket_recvfrom(handle->h, buffer, len);
D("message received, ret: %d", ret);
while (ret > 0) {
ret = mnl_cb_run2(buffer, ret,
handle->seq, handle->portid,
handle->cb_ctl[NLMSG_MIN_TYPE],
handle->data,
handle->cb_ctl, NLMSG_MIN_TYPE);
D("nfln_cb_run2, ret: %d", ret);
if (ret <= 0)
break;
ret = mnl_socket_recvfrom(handle->h, buffer, len);
D("message received, ret: %d", ret);
}
return ret > 0 ? 0 : ret;
}
static struct ipset_handle *
ipset_mnl_init(mnl_cb_t *cb_ctl, void *data)
{
struct ipset_handle *handle;
assert(cb_ctl);
assert(data);
handle = calloc(1, sizeof(*handle));
if (!handle)
return NULL;
handle->h = mnl_socket_open(NETLINK_NETFILTER);
if (!handle->h)
goto free_handle;
if (mnl_socket_bind(handle->h, 0, MNL_SOCKET_AUTOPID) < 0)
goto close_nl;
handle->portid = mnl_socket_get_portid(handle->h);
handle->cb_ctl = cb_ctl;
handle->data = data;
handle->seq = time(NULL);
return handle;
close_nl:
mnl_socket_close(handle->h);
free_handle:
free(handle);
return NULL;
}
static int
ipset_mnl_fini(struct ipset_handle *handle)
{
assert(handle);
if (handle->h)
mnl_socket_close(handle->h);
free(handle);
return 0;
}
const struct ipset_transport ipset_mnl_transport = {
.init = ipset_mnl_init,
.fini = ipset_mnl_fini,
.fill_hdr = ipset_mnl_fill_hdr,
.query = ipset_mnl_query,
};
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